The Morphology and Imaging Core is critical to the support of the studies proposed. The function of the Morphology and Imaging Core is briefly outlined in four areas: 1) To provide and process specimens for in situ hybridization and immunohistochemistry; 2) To provide a facility for imaging, data, data storage and retrieval; 3) To provide training and support for all aspects of morphological analysis; and 4) To assay selected protein and gene markers to provide a comprehensive analysis of coronary vessel development. The Morphology and Imaging Core will focus our resources to provide consistent, state-of-the-art tissue processing, imaging and analysis for each Project. The Core will also act as a mechanism to disseminate results between Projects and to develop, create and maintain a comprehensive data base for gene expressing in the developing and mature coronary vasculature. Given the reliance of each project on morphological analysis, each Project will use a significantg amount of the resources available in the Morphology and Imaging Core. The support of this Core is essential to completing the stated aims of each of the four individual projects.